tests/run-tests: Skip frozenset tests if set literal syntax is not available.

tests/run-tests

@@ -314,7 +314,7 @@ def run_tests(pyb, tests, args):
         test_name = os.path.splitext(test_basename)[0]
         is_native = test_name.startswith("native_") or test_name.startswith("viper_")
         is_endian = test_name.endswith("_endian")
-        is_set_type = test_name.startswith("set_")
+        is_set_type = test_name.startswith("set_") or test_name.startswith("frozenset")
 
         skip_it = test_file in skip_tests
         skip_it |= skip_native and is_native